Semiconductor image devices that convert images into electrical signals have been developed. Types of image devices include Charge Coupled Devices (CCD) and CMOS image devices. A CCD device includes a plurality of MOS capacitors, where each MOS capacitor may operate by moving carriers generated by light. A CMOS image device may includes a plurality of unit pixels and a CMOS logic circuit controlling output signals of the unit pixel.
As illustrated in example FIG. 1, a CMOS image sensor 10 may include a plurality of different color filters in a unit pixel (e.g. blue color filter 2, green color filter 3, and red color filter 4 in a unit pixel) which each selectively transmit different colors of light, while filtering white light. Each unit pixel may include a plurality of pixels, with each pixel including one color filter. The plurality of color filters may be formed over a semiconductor substrate 1. Planar layer 5 may be formed over the plurality of color filters to compensate for height differences between different types of color filters (e.g. the height difference between blue color filter 2 and green color filter 3 and red color filter 4). A lens 6 may be formed in each pixel over planar layer 5 to focus light through the color filter in that pixel (e.g. lens 6 may be formed over blue color filter 2 to focus light through blue color filter 2.
An active semiconductor element may be formed under each color filter in each pixel, which converts the filtered light into an electrical signal. For example, in a blue pixel an active semiconductor element may be formed below blue color filter 2 to produce an indicative electrical signal in response to blue light passing through blue color filter 2 and in a green pixel an active semiconductor element formed below green color filter 3 may produce a separate indicative electrical signal in response to green light passing through green color filter 3.
However, when the color filters are formed adjacent to each other, gaps may occur between the color filters (e.g. the gap between blue color filter 2 and green color filter 3 or the gap between green color filter 3 and red color filter 4). These gaps may cause optical problems such a cross talk and/or noise between adjacent pixels. For example, light that is directed into the gaps may be misdirected into the color filters in an uncontrollable manner. Cross talk and/or noise may degrade the quality of an image sensor by reducing an image sensor's sensitivity to light and/or reducing the resolution of an image sensor.